反应详情

温度

0 °C

To an ice cooled suspension of 4-benzyloxy-2-hydroxybenzaldehyde (P1) (2.28 g, 10 mmol) in 10 mL of methanol was slowly added sodium borohydride (0.38 g, 10 mmol). After addition of sodium borohydride, a clear solution was obtained. The reaction was stirred at 0° C. for 20 minutes followed by stirring at RT for 10 minutes. The solvent was evaporated under vacuum. To this solid residue was carefully added 0.1 N H2SO4 until the pH dropped to 6.5 with vigorous stirring. Additional water (ca. 100 mL) was added with continuous stirring which then caused the product to precipitate. The solid was filtered and copiously washed with water to remove all traces of acid (last wash pH≧7). The solid was immediately vacuum dried to obtain (1.75 g, 76%) of P2 as a white solid: mp 88-90° C.; TLC, Rb0.29, in hexanes:EtOAc (2:1); 1H NMR (600 MHz, DMSO-d6) δ, 9.36 (s, 1H, Ph-OH), 7.43-7.32 (m, 5H, C6H5), 7.13 (d, 1H, J=8.4 Hz, Ar—H6), 6.44-6.41 (m, 2H, Ar—H5/Ar—H3), 5.01 (s, 2H, PhCH2), 4.8 (t, 1H, CH2OH), 4.39 (s, 2H, OHCH2).

1. customa clear solution was obtained
2. stirringby stirring at RT for 10 minutes
3. customThe solvent was evaporated under vacuum
4. additiondropped to 6.5 with vigorous stirring
5. additionAdditional water (ca. 100 mL) was added
6. stirringwith continuous stirring which
7. customto precipitate
8. filtrationThe solid was filtered
9. washcopiously washed with water
10. customto remove
11. washall traces of acid (last wash pH≧7)
12. customdried
13. customto obtain (1.75 g, 76%) of P2 as a white solid